2014 Feb 3
Dear Tracy Withrow, NCTM,
A year ago you answered my question about who wrote the
standard for teaching measurement. Thank you. All year I have been
digesting what you said and reading the ASTM Measurement Standard.
We in the metric community think that the teaching of
measurement in K-12 schools is not well done. Because Congress has
not called for no longer using what we call inch-pound units (what the
NCTM standard calls "customary" units) teachers and NCTM are forced to
teach both sets of units. (Note however, Congress has said in law that
metric units (officially SI units) are preferred for all government work.)
This leads to problems, the worst of which is the teaching of
conversion. Many (most?) teachers teach both sets together and expect
students to think of the two together. This results in students not
being able to live in a metric world.
There is some thought that a reason that Detroit is bankrupt is
that workers in metric manufacturing make many mistakes (expensive)
because they do not live in a metric world and so make errors in metric
manufacturing.
Metric units should be taught without reference to inch-pound units.
Minimize the use of centimeter. Do not use centimeter in examples.
Conversion should not be taught until algebra is taught.
Inch-pound units could well be put in history class.
The ASTM MeasuremenT Standard says what students should know and
do but does not say what teachers should know and do. Please add to the
standard what teachers should know and do.
In Boulder there are no millimeter-only rulers for sale. This makes
it hard to teach metric because the inch is always there. NCTM should use
its influence to get millimeter-only rulers on the market.
Math text books mix up the two sets of units so students, who do
not live in a metric world, do not learn to use metric units. I urge NCTM
to use its influence to get publishers to clean up their measurement texts
to clearly separate metric and inch-pound units.
I hope you find these comments useful. Please tell me if they help.
Robert H. Bushnell
[email protected]
-----------------------------------------------
On Dec 18, 2012, at 5:35 PM, Tracy Withrow wrote:
> Mr. Bushnell,
>
> Thank you for contacting the National Council of Teachers of
> Mathematics--we appreciate your interest.
>
> The Measurement Standard was written by a group of writers that produced
> Principles and Standards for School Mathematics, which was published in
> 2000. The writers represented a cross section of experienced
> mathematics educators.
>
> Hopefully this information helps, but please feel free to contact me if
> you have additional questions.
>
> Regards,
>
> Tracy Withrow | National Council of Teachers of Mathematics |
> Communications Manager
> 1906 Association Drive | Reston, VA 20191 | 703.620.9840 x2189 |
> [email protected]
>
>
>
> -----Original Message-----
> From: Robert H. Bushnell [mailto:[email protected]]
> Sent: Thursday, November 08, 2012 4:21 PM
> To: NCTM
> Cc: USMA
> Subject: NCTM Web Site Feedback
>
> Referring page:
> http://www.nctm.org/standards/content.aspx?id=316#understand
>
>
> 2012 Nov 5
> National Council of Teachers of Mathematics
>
> Who writes the content of the Measurement Standard?
>
> Please help by telling me how NCTM measurement policy is
> developed.
>
> Robert H. Bushnell PhD PE
> 502 Ord Drive
> Boulder, Colorado 80303-4732
>
